Connecting device for a catheter

ABSTRACT

A device for connecting a catheter with a container for contrast medium which is subjected to pressure is characterized by coupling means which are liquid-tightly connected with each other, at least one of these means being mounted so as to be rotated relatively to the other means about the flow axis. These means can be removably connected by connecting elements with the container for the contrast medium on the one hand and with the catheter on the other hand.

United States Patent 11 1 Adelhed Jan. 15, 1974 CONNECTING DEVICE FOR ACATHETER 3,058,761 10/1962 Christophersen 285/281 [75] Inventor: Ter JeRoj Enok Adelhed, 285m x Jakobsberg, Sweden 3,167,330 l/l965 Draudt8/1909 Walder '[73] Assrgnee. Siemens Aktlengesellschaft, 929'734Erlangen Germany 980,776 l/l9ll I-Iavdsocg 285/275 Filed: Jan. 1972FOREIGN PATENTS OR APPLICATIONS 844,720 4/1939 France l28/2l4 R [21]Appl. No.: 220,843

r Primary Examiner-Thomas F. Callaghan [30] Foreign Application PriorityData Att0meyRlchards & Gelel' F b. I, 971 S d ll867l we I 57 ABSTRACT[52] US. Cl. 285/169, 128/2 R, 128/214 R, A device for connecting acatheter with a container 128/348, 285/278 for contrast medium which issubjected to pressure is [51] Int. Cl A6lm 5/00,'F16l 27/00characterized by coupling means which are liquid- [58] Field of Search285/278, 281, 280, tightly connected with ea h h at least n f these285/275, 272, 11, 169; 128/334 C, 348, DIG. means being mounted so as tobe rotated relatively to 9, 214 R the other means about the flow axis.These means can be removably connected by connecting elements with [56]-References Cited the container for the contrast medium on the one UNITEDSTATES PATENTS hand and with the catheter on the other hand.

2,893,395 7/1959 Buck 128/DIG. 9 1 Claim, 2 Drawing Figures ii I . 7 a t-L2 16 g v 7 22 LI 4-4, A\3B 40 ze i PATENTED m 1 5m SHEET 1 [IF 2CONNECTING DEVICE FOR A CATHETER This invention relates to a device forconnecting a catheter with a container for contrast medium which issubjected to pressure.

It is known to introduce a catheter consisting of thin plastic or metaltubes, for example, into blood organs and then to connect it to acontainer for contrast medium subjected to pressure. When contrastmedium begins to flow in, the catheter is subjected to high pressure bythis medium, so that it can carry out uncontrolled movements and damagethe blood vessels. Obviously it is of great importance to prevent thesedamaging catheter movements in a blood vessel.

It was determined, with surprise, that when the catheter is not fixed atits outer end directed toward the pressure medium container, but iscapable of moving freely about its longitudinal axis, it is preventedfrom carrying out these detrimental movements.

Therefore, an object of the present invention is the provision ofconnecting means providing a complete seal and yet making possible afree rotation of the catheter relatively to the contrast mediumcontainer.

Other objects of the present invention will become apparent in thecourse of the following specification.

In the accomplishment of the objectives of the present invention it isfound desirable to provide coupling means which are liquid-tightlyconnected with each other, at least one of these means being mounted soas to be rotated relatively to the other means about the flow axis,whereby the means can be removably connected by connecting elements withthe contrast medium container on the one hand and with the catheter onthe other hand. 7

According to an advantageous embodiment of the present invention thecoupling means consist of a cylinder provided with a cover closing atleast one of its front surfaces. A piston sealed against the cylinderwalls is introduced into the cylinder and is mounted so as to berotatable about the longitudinal axis of the cylinder. The piston issecured against sliding out. The cylinder has a flow channel for theflow of the contrast medium into its interior, the channel being closedby a connecting element. The piston has a flow channel closed by anotherconnecting element for the flow of the contrast medium outwardly fromthe interior of the cylinder. This device which is similar in itsstructure to an injection syringe, solves the main object of the presentinvention in a surprisingly simple technically manufacturing manner.

According to a further development of the present invention the couplingmeans consist of two pistons introduced into the cylinder and securedagainst sliding out, the pistons being rotatable about the longitudinalaxis of the cylinder. Each of the pistons has a flow channel providedwith a separate connecting element for the flow of the contrast mediumfrom one connecting element into the interior of the cylinder and thenoutwardly to the other connecting element. Practical experience hasshown that this double rotating capacity provides better workingconditions.

According to still another development of the present invention aparticularly good seal against the outgoing contrast medium is producedwhen the cylinder can be closed at the front sides up to the flowchannels and when the surfaces of the covers and pistons extendingtoward each other and at right angles to the axis of the cylinder areshaped as superior joints.

Furthermore, the present invention makes it possible for one of thepistons to run particularly softly, whereby only this piston must beprovided with special bearing means, and to provide a good scaling forthis piston. For that purpose a further piston is provided between thatpiston which is directed toward the catheter and the cover. Thisadditional piston is introduced with liquid seal into the cylinder andit has a concentrical axial bore through which passes the shaft of theadjacent piston. This shaft is rotatable about the longitudinal axis ofthe cylinder and is also sealed against liquid. Frictionally poorbearing means are introduced between the surfaces of the two pistonswhich are directed toward each other and extend at right angles to theaxis of the cylinder.

The invention will appear more clearly from the following detaileddescription when taken in connection with the accompanying drawingsshowing by way of example only, a preferred embodiment of the inventiveidea.

In the drawings:

FIG. 1 is a diagram illustrating the main features of a device forcatheterizing a patient.

FIG. 2 is a side view, partly in section, of a connecting device inaccordance with the present invention.

According to FIG. 1 an automatically operated high pressure injectionsyringe 1 supplies dosed amounts of contrast medium during predeterminedtime periods through a hose 2 to the catheter 3 which is introduced intoan arm vein of a patient 5 lying upon the table 4 of an X-ray device(not shown). The high pressure injection syringe 1 has an operatingsection 6 with setting means 7 and 8 for the amount of the contrastmedium and the duration of the injection, as well as a button 9 forreleasing the flow of the contrast medium which can be also'operatedautomatically, for example, depending upon the heart phase of thepatient 5.

The contrast medium is located in the spray cylinder 10 which isconnected with the operating section 6 by holding elements 11 and 12.The spray piston 13 is connected by a connecting rod 14 with a lever 15which actuates the spray piston 13 depending upon values selected by thesetting means 7 and 8.

In order to avoid the transmission of forces appearing in the hose 2 asthe result of high pressure of the contrast medium to the catheter 3,the hose 2 carries a connecting device 16 which is shown in detail inFIG. 2.

This connecting device 16 has a cylinder 17 which may consist entirelyof metal or of a glass tube having metallic end caps, as used in knowninjection syringes. One end of the cylinder is closed by a front wall18. A piston 19 having a seal 20 is introduced into the upper part ofthe cylinder 17. The flow channel of the piston for the contrast mediumis formed by a cylindrical shaft 21 extending through a concentric boreof the front surface 18 of the cylinder 17. The outer end of the shaftcarries a connecting element 25 shaped as a box coupling for connectingthe device with the pressure container (not shown) for the contrastmedium. In order to provide a flow for the contrast medium the cylinderand the shaft have a channel 23 extending in the longitudinal direction.

The end surface of the piston 19 directed toward the front cover 18, aswell as the surface of the cover 18 directed toward the piston extend atright angles to the central axis of the cylinder 17 and are so groundthat the two surfaces tightly engage each other forming a so-calledsuperior joint.

The cylinder 17 also contains a second piston 27'similar in shape to thefirst piston 19 and arranged also with fine fitting in the lower part ofthe cylinder. A flow channel 31 extends longitudinally through thepiston 27 and its shaft 29. At the end of the shaft 29 there is afurther coupling member 33 having the shape of a plug coupling forproviding a liquid-tight connection between the channel 31 and acatheter.

The front surfaces of the two pistons 19 and 27 extend at right anglesto the longitudinal axis of the cylinder and are separated from eachother by a small intermediate space 22.

A third piston 37 is located between the surface of the piston 27directed toward the catheter and the cover 39 of the cylinder 17. Thecylindrical shaft 29 which is concentrical to central axis of thecylinder, is freely rotatable in the piston 37 and extends through itwith liquid-tight seal. The piston 37 is also introduced into thecylinder 17 with a sealing slide, The front surface of the piston 37extending toward the catheter also engages the inner surface 40 of thecover 39 with a socalled superior joint. The inner surface 40 of thecover 39, just as the front surface of the cover 18, is also preferablysurface ground and extends at a right angle to the axis of the cylinder.

The cover 39 has a concentric bore, similar to that of the piston 37,and the shaft 29 is rotatably mounted in that bore with fine fitting.The cover 39 can be screwed upon the outer surface of the cylinder 17 byscrew threads 41. The surfaces of the pistons 27 and 37 which face eachother also extend at a right angle to the axis of the cylinder. Axialball bearings 35 are located between these surfaces.

The operation of the described device is as follows:

Liquid contrast medium is introduced under pressure into the connectingelement and flows through the channel 23 in the direction of the arrow26. The fine sealing of the engaging surfaces between the piston 19 andthe cylinder 17 results in that the contrast medium cannot penetrate tothe bore of the front cover 18. This seal is also strengthened by thefine joint engagement of the front surface of the piston 19 with theinner ground surface 24 of the cover 18.

The contrast medium penetrates through the channel 23 into the space 22between the pistons 19 and 27 and then flows through the channel 31 andthe coupling member 33 to the catheter in the direction of the arrow 34.

The device composed of the piston 27 with the shaft 29 and theconnecting element 33 must easily rotate in the cylinder 17 whileremaining sealed and must be able to move slightly axially. For thatpurpose a frictionally poor bearing consisting of ball bearings 35 isprovided between the piston 27 and the piston 37. The space 22 betweenthe two pistons 19 and 27 has the purpose to prevent any difficulty inthe rotation of the piston 27 which could occur if the two opposed frontsurfaces of the pistons 19 and 27 would be in engagement. The piston 37does not serve essentially as a seal but to guide the shaft 29 of thepiston 27; its front surface directed toward the interior of thecylinder serves as a support for the ball bearings 35.

The construction of the piston 37 in such manner that it can be shiftedwith slide seal into the cylinder 17,

has essentially the manufacturing reason that the device can be composedof pistons of the same diameter and of at least approximately equallengths. Furthermore, the manufacture is simplied in that the twopistons 19 and 27 with their shafts 21 and 29 and extending channels 23and 31 have essentially the same structure. In addition, the describedconstruction with three pistons results in a higher safety as far asseal is concerned.

It is basically possible to eliminate the piston 37 and to provide thefriction-poor bearing consisting of balls 35 between the inner surface40 of the cover 39 and the opposed front surface of the piston 27.

However, by keeping the piston 37 and providing a fine adjustmentbetween the shaft 29 and the channel 31 in the piston 37 and a fineadjustment between the outer surface 38 of the piston 37 and the innersurface of the cylinder 17, a greater security is provided for thecontrast medium which could penetrate between the outer surface 38 ofthe piston 37 and the inner surface of the cylinder 17. The contrastmedium will penetrate outwardly, since the pressure in the range of theball bearings 35 is small as long as this intermediate space is notcompletely filled with the contrast medium.

In order to further improve the sealing, the outer surface of the piston27 is provided with an annular groove 43. As long as this groove is notcompletely filled with liquid, the pressure between the hollow of thegroove 43 and the intermediate space at the ball bearings 35 is small,and thus prevents to a substantial extent the passage of the mediumalong the outer wall of the piston 27.

It is also basically possible to eliminate the piston 19 by firmlyconnecting the shaft 21 with the cover 18 or making the two of onepiece.

However, there is an advantage of having the piston 19 which in theillustrated construction is provided with an annular groove 42 in amanner similar to that of piston 27. This advantage consists in beingable to provide a relative rotary movement between the cylinder 17 onthe one hand and the device consisting of the piston 19, the shaft 21and the connecting element 25 on the other hand. This provides thepossibility of a double rotary movement between the two connectingelements 25 and 33.

I claim:

1. A device for connecting a catheter with a container for a contrastmedium, said container being subjected to pressure, said devicecomprising coupling means having a cylinder, a connecting elementremovably connecting said cylinder with said container and having achannel for the flow of the contrast medium, another connecting elementremovably connecting said cylinder with said catheter and having achannel for the flow of the contrast medium, covers closing both ends ofthe cylinder and having openings for said channels, a first pistonliquid tightly mounted in said cylinder and directed to thefirst-mentioned connecting element,

' said piston having a transverse axial passage coaxial with saidcylinder and communicating with the firstmentioned channel, a secondpiston liquid tightly mounted in said cylinder and directed to thesecondmentioned connecting element, said second piston having atransverse axial bore, a third piston located between the first andsecond pistons and liquid tightly mounted in said cylinder, said thirdpiston being spaced from said first piston, a shaft firmly connectedwith said between the second and third pistons, whereby the third pistonand its shaft are rotatable relatively to the first piston.

1. A device for connecting a catheter with a container for a contrastmedium, said container being subjected to pressure, said devicecomprising coupling means having a cylinder, a connecting elementremovably connecting said cylinder with said container and having achannel for the flow of the contrast medium, another connecting elementremovably connecting said cylinder with said catheter and having achannel for the flow of the contrast medium, covers closing both ends ofthe cylinder and having openings for said channels, a first pistonliquid tightly mounted in said cylinder and directed to thefirst-mentioned connecting element, said piston having a transverseaxial passage coaxial with said cylinder and communicating with thefirst-mentioned channel, a second piston liquid tightly mounted in saidcylinder and directed to the second-mentioned connecting element, saidsecond piston having a transverse axial bore, a third piston locatedbetween the first and second pistons and liquid tightly mounted in saidcylinder, said third piston being spaced from said first piston, a shaftfirmly connected with said third piston and extending through the boreof said second piston and to the second-mentioned connecting element,said third piston and said shaft having a continuous transverse axialpassage constituting a continuation of the first-mentioned axialpassage, and ball bearings between the second and third pistons, wherebythe third piston and its shaft are rotatable relatively to the firstpiston.